Lifting Strength via pushing downgrade?

[Furudo_Erika]

I'm going to keep this pretty simple; I'm not entirely fond of Lifting Strength feats by pushing something as it is calculated by the mass of the object being pushed. However, it is a lot easier pushing an object than actually lifting the object due to friction. For example, a person can push a 1,000kg car because of friction between the tires and road, but they are not able to deadlift the car.
By this logic, using mass alone to calculate feats by pushing would make a lot of average humans have Class 5 Lifting Strength.

 

[Furudo_Erika]

I thought of making this thread whenever I seen this calculation: https://vsbattles.fandom.com/wiki/User_blog:DragonGamerZ913/Sora_Pushes_a_Boulder

Class 10 just sounded way too high for me, so I made a (very rough) recalculation in the comments using the friction coefficient of sand and acceleration due to displacement, obtaining much more reasonable results in my opinion. I will admit, it is not a perfect calculation, but it is a rough estimation.

 

[Valiant_Abyss]

Following.

 

[ElixirBlue]

For example, a person can push a 1,000kg car because of friction between the tires and road, but they are not able to deadlift the car.

Man lifts Car

I thought of making this thread whenever I seen this calculation: https://vsbattles.fandom.com/wiki/User_blog:DragonGamerZ913/Sora_Pushes_a_Boulder

This Chris Thorndyke faker seems pretty strong.

 

[Arcker123]

Iirc there are plenty of stories of mothers lifting cars to save their children.

 

[Furudo_Erika]

As in, pushing the side of a car upwards to pull them out...or lifting the entire vehicle off the ground?
The former being much easier to do as you only have to move a fraction of the mass, rather than the whole thing.

 

[Furudo_Erika]

For example: I can easily lift one side of my leather sofa (Which weighs around 224lbs; 101.587kg) over my head using only a single hand.
However...there is a little something called "center of mass", in which the sofa being symmetrical, I can say its center of mass is well...in the center. So by lifting one side of the sofa, I am effectively only lifting half of its mass; 50.794kg (Barely Average Human).
Same concept applies to "lifting" a car.

 

[DarkDragonMedeus]

For pushing and pulling feats, we also multiply by acceleration; but yes it doesn't normally fully scale to the mass of the entire object. Though, if there's no friction; like a giant rock on non-slippery soil where there is no wheels; I here being able to lift 0.45x the strength is often the case.

 

[Firestorm808]

We should be taking physics into account with factors such as leverage, friction, normal force, and etc,

 

[Furudo_Erika]

How about lifting strength when halting a moving object, since it is always harder to stop a fast moving object rather than the same object moving more slowly? As you would need to transfer the same amount of momentum to the object to stop it.

When dealing with fast moving objects, I believe the pushing feat to stop an object would actually be greater than the mass. After all, its sounds more impressive for someone to stop and catch a train at full speed in their tracks, rather than simply lifting it in my opinion. Pushing it back is an even greater feat, as not only are they exerting the same force in order to to stop it, but even more force to fight back against it as it tries to move forward.
As such, I believe halting a train moving at full speed is more like Class M, rather than Class K.

In cases like these...I probably have to use momentum, as I can never find the time interval in which an object decelerates. Hell, it can even take mere milliseconds for an object to come to a stop. Also, it is always harder to stop the same object when it is moving faster than more slowly, regardless of its acceleration.

 

[Firestorm808]

Weight/Force is just mass times acceleration, so if a 100 kg train going 100 m/s is stopped in 1 second, then the weight would be 10000 Newtons or 1019.716 kg force.

 

[Furudo_Erika]

Oof, I know that 100kg is just an example, but that's...a pretty light train.
The N700 Series Shinkansen trains have a mass of about 715,000kg with a maximum velocity of 300 km/h (83.333 m/s).
If a character stopped that train in a second, it would equal about 59,583,100 Newtons, or 6,073,710.5 kg-force (Class M).

 

[Antoniofer]

We already took friction into account when doing calcs (or at least I see few calcs doing it some time ago); its just matter of determinating the friction constant (depends of the terrain) and then multiplying it by the mass of the object.

 

[Jasonsith]

Following

In fact, a careful pick of friction coefficient of material and surface condition can lower the lifting strength required to a reasonable level.
In fact, I have my own weird example.

Also, about force required to decelerate and stop a moving object and pushing an object to moving at an acceleration, that can be tricky, as speedsters are usually portrayed to throw objects at high speed but cannot lift as much (even with a slower acceleration) even though the force to do so is exactly the same. I am elaborating this problem in another thread.